Two popular churches in the same downtown North Texas city received anonymous bomb threat letters warning them to cancel their Christmas Eve services, although both refuse to be intimidated and plan to worship with added police protection.

The threatening letters arrived at the Denton Bible Church on Monday and at St. Andrew Presbyterian Church on Tuesday, the Denton Record-Chroniclereported. “Both letters were similar in makeup,” said Denton Police Department spokesman Shane Kizer, “It was a short letter. Just a few sentences.”

The unaffiliated houses of worship are in the City of Denton, located at the very northern tip of the Dallas-Fort Worth area. Denton may be known best for its 2014 controversial fracking ban that ended this year with legislation that banned fracking bans.

Kizer said the letters mentioned bombs and warned both churches against holding their Christmas Eve services, according to KTVT 11 (CBS). The police spokesman did not address specifics of the letter so not to interfere with the investigation now taking place, although he added that neither threat indicated any religious or social affiliation of its author. Kizer noted anytime there is a threat of a bomb, there could be mass casualties and officers want to take “as many precautions as possible to prevent that from happening,” although he acknowledged law enforcement did not know yet if this was real or a hoax.

Denton police suspect the same person is responsible for both bomb threat letters and are searching for this mysterious individual. Kizer said: “It could be a hate-related crime. These are both Evangelical churches, so it could be towards that or it could be someone wanting to cause alarm or cause panic.”

Nonetheless, both churches still plan to hold their Christmas Eve services. On Facebook, Tom Nelson, senior pastor at Denton Bible Church issued a cheeky statement. He wrote, in part:

You’ve probably heard by this time if you watch the news that we have had our first gen-u-ine bomb threat. It came in the mail Monday afternoon from a gen-u-ine super villain. Wouldn’t you know, it came 24 hours after I had boasted of our fair city’s apathy versus Dallas’s tirades.

Anyway, though this letter was not from Lex Luthor, The Joker or even The Penguin, we still must take all threats seriously and we shall. We shall have Christmas Eve as always but you will notice more folks at the entrances with more eyes.

Nelson also posted: “We don’t yield to fear. We are Christians.” He confirmed the service is on and suggested that with added police protection and security accommodations to ensure everyone’s safety, “make things simple by not bringing a backpack, a package, or some big bulky anything, lest a choir member frisk you or strip search you. Nothing kills the Christmas spirit quicker.”

St. Andrew Presbyterian Church issued a letter yesterday to its members indicating the congregation will not succumb to fear. “Once it hit the news that this was going on, we felt it better to make a statement so that everyone is on the same page,” Rev. Alan Baroody, interim pastor at Saint Andrews, told KXAS 5 (NBC). He emphasized the importance for the community that Christmas Eve services are held.

Kizer told the Denton newspaper to expect an increased police presence around all of Denton’s places of worship.

“When people are planning to carry out some kind of terror attack, they don’t normally give a warning beforehand,” Kizer told the Denton Record-Chronicle. “[But] you have to take them seriously, and obviously, we’re taking this one seriously with all the things happening around the country.” He added, “We will do everything we can to keep our citizens safe.”

Denton police acknowledge they contacted the Department of Homeland Security about these threats but did not say if federal agents are involved in the investigation.